cad/brickutils: drop dependency on py-xml
According to project documentation and source review/runtime tests this port
doesn't using py-xml, so remove it and bump PORTREVISION.
Add NO_ARCH and limit python version to 2.x while here (because of pygtk2).
With hat: python

cad/brickutils: unbreak fetch (relocated at sourceforge)
There's a new version of brickutils, so the distinfo file was moved to
an "obsolete" folder. Adjust MASTER_SITES accordingly.
Approved by: blanket